A silent discharge occurs when disposing a dielectric between two electrodes secured on each end and applying a high alternating current voltage or a periodic pulsed voltage between the electrodes. In the resulting plasma field, active species, radicals, and ions are produced to promote a gaseous reaction and decomposition. This phenomenon may be utilized to remove toxic components in exhaust gas discharged from an engine, an incinerator, or the like.
A plasma reactor or the like has been disclosed which treats NOx, carbon particulate, HC, CO, or the like in exhaust gas discharged from an engine, an incinerator, or the like by causing the exhaust gas to pass through a plasma field (see patent document 1).    Patent document 1: JP-A-2001-164925